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Methods for controlling the galactosylation profile of recombinantly-expressed proteins

Abstract: The present invention relates to methods for modulating the glycosylation profile of recombinantly-expressed proteins. In particular, the present invention relates to methods of controlling the galactosylation profile of recombinantly-expressed proteins by supplementing production medium, e.g., a hydrolysate-based or a chemically defined medium, with manganese and/or D-galactose.

Agent: Abbott Laboratories - Abbott Park, IL, US
Inventors: Cornelia T. Bengea, Lisa M. Rives
USPTO Applicaton #: #20120276631 - Class: 435404 (USPTO) - 11/01/12 - Class 435
Related Terms: Manganese Profile Proteins

The Patent Description & Claims data below is from USPTO Patent Application 20120276631, Methods for controlling the galactosylation profile of recombinantly-expressed proteins.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser. No. 61/479,727, filed Apr. 27, 2011, which is also incorporated herein by reference in its entirety.

1. INTRODUCTION

The present invention relates to methods for modulating the glycosylation profile of recombinantly-expressed proteins. In particular, the present invention relates to methods of controlling the galactosylation profile of recombinantly-expressed proteins by supplementing production media with manganese and/or galactose.

BACKGROUND OF THE INVENTION

Utilization of a particular type of production media, e.g., hydrolysate-based media or chemically defined media (“CD” or “CDM”), for CHO cell cultures producing recombinant proteins can enhance cell growth and target protein production. However, recombinant proteins produced in different CD or hydrolysate-based media can exhibit large differences in their product quality profile. In certain instances, this variability can lead to increases in the fraction of the agalactosyl fucosylated biantennary oligosaccharides NGA2F+NGA2F-GlcNAc and decreases in the fraction of galactose-containing fucosylated biantennary oligosaccharides NA1F+NA2F. Shifts in the glycosylation profile of recombinant proteins of this magnitude are significant as these shifts may render the resulting production lots of the target protein out of compliance with approved process specifications.

SUMMARY

OF THE INVENTION

In certain embodiments, the present invention is directed to methods of controlling the galactosylation profile of recombinantly-expressed antibody. In certain embodiments, the recombinantly-expressed antibody is an anti-TNFα antibody. In certain embodiments, the recombinantly-expressed anti-TNFα antibody is adalimumab.

In certain embodiments, the present invention is directed to methods of controlling the galactosylation profile of recombinantly-expressed proteins by supplementing a production medium, e.g., a hydrolysate-based or a CD medium, used in the production of recombinantly-expressed proteins with a sufficient amount of manganese and/or a manganese-containing supplement to achieve the following manganese concentrations in the production media: at least about 0.1, at least about 0.2, at least about 0.5, at least about 1.0, at least about 10, at least about 20, at least about 25, at least about 40, at least about 50, at least about 60, at least about 75, at least about 80, or at least about 100 μM, wherein that production media is used to dilute a supplement-free cell culture growth media containing no supplement by a ratio of about 1:4 or about 1:5 (supplement-free growth media:supplemented production media). In certain embodiments, the present invention is directed to methods of controlling the galactosylation profile of recombinantly-expressed proteins by supplementing a production medium, e.g., a hydrolysate-based or a CD medium, used in the production of the recombinantly-expressed proteins with sufficient galactose and/or galactose-containing supplement to achieve the following galactose concentrations in the production media: at least about 1, at least about 4, at least about 5, at least about 10, at least about 15, at least about 20, at least about 30, at least about 40, at least about 60, or at least about 100 mM, wherein that production media is used to dilute a supplement-free cell culture growth media containing no supplement by a ratio of about 1:4 or about 1:5 (supplement-free growth media:supplemented production media).

4. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts the culture performance of adalimumab-producing CHO cell line in CDM GIA-1 in batch shake flasks (A) Culture growth; (B) Viability; (C) Normalized titer.

FIG. 2 depicts the culture performance of adalimumab-producing CHO cell line in CDM GIA-1 in fed-batch 3L bioreactors (A) Culture growth; (B) Viability; (C) Normalized titer.

FIG. 3 depicts the galactosylation profile of adalimumab in CHO cell line in CDM GIA-1 in batch shake flasks (A) NGA2F+NGA2F-GlcNac; (B) NA1F+NA2F.

FIG. 4 depicts the percentage galactosylation change of adalimumab in CDM GIA-1 in batch shake flasks relative to control.

FIG. 5 summarizes the effect of manganese and/or galactose addition to CDM GIA-1 on galactosylation of adalimumab relative to control in CHO cell line.

FIG. 6 depicts the galactosylation profile of adalimumab in CHO cell line in CDM GIA-1 in fed-batch 3L bioreactors (A) NGA2F+NGA2F-GlcNac; (B) NA1F+NA2F.

FIG. 7 depicts the culture performance of CHO cell line in CDM HyClone CDM4CHO in batch shake flasks (A) Culture growth; (B) Viability.

FIG. 8 depicts the galactosylation profile of adalimumab in CHO cell line in CDM HyClone CDM4CHO in batch shake flasks (A) NGA2F+NGA2F-GlcNac; (B) NA1F+NA2F.

FIG. 9 summarizes the effect of manganese and/or galactose addition to CDM HyClone CDM4CHO on galactosylation of adalimumab relative to control in CHO cell line.

FIG. 10 depicts the culture performance of CHO cell line in hydrolysate media in batch shake flasks (A) Culture growth; (B) Viability.

FIG. 11 depicts the galactosylation profile of adalimumab in CHO cell line in hydrolysate media in batch chake flasks (A) NGA2F+NGA2F-GlcNac; (B) NA1F+NA2F.

FIG. 12 summarizes the effect of manganese and/or galactose addition to hydrolysate media on galactosylation of adalimumab relative to control in CHO cell line.

FIG. 13 depicts the culture performance of adalimumab-producing CHO cell line #2 in CDM GIA-1 in batch shake flasks (A) Culture growth; (B) Viability.

FIG. 14 depicts the galactosylation profile of adalimumab in CHO cell line #2 in CDM GIA-1 in batch shake flasks (A) NGA2F+NGA2F-GlcNac; (B) NA1F+NA2F.

FIG. 15 summarizes the effect of manganese and/or galactose addition to CDM GIA-1 on galactosylation of adalimumab relative to control in CHO cell line #2.

FIG. 16 depicts culture performance of adalimumab-producing CHO cell line #3 in CDM GIA-1 in fed-batch 3L bioreactors (A) Culture growth; (B) Viability; (C) Normalized titer.

FIG. 17 depicts the galactosylation profile of adalimumab in CHO cell line #3 in CDM GIA-1 in fed-batch 3L bioreactors (A) NGA2F+NGA2F-GlcNac; (B) NA1F+NA2F.

FIG. 18 summarizes the effect of manganese and/or galactose addition to CDM GIA-1 on galactosylation of adalimumab relative to control in CHO cell line #3.

FIG. 19 depicts the culture performance of adalimumab-producing NS0 cell line in CDM PFBM-3/PFFM-4 fed-batch shake flasks (A) Culture growth; (B) Viability; (C) Normalized titer.

FIG. 20 depicts the galactosylation profile of adalimumab in NSO cell line in CDM PFBM-3/PFFM-4 fed-batch shake flasks (A) NGA2F+NGA2F-GlcNac; (B) NA1F+NA2F.

FIG. 21 summarizes the effect of manganese and/or galactose addition to CDM PFBM-3/PFFM-4 on galactosylation of adalimumab relative to control in NSO cell line.

FIG. 22 depicts the culture performance of CHO cell line producing mAb #1 in CDM GIA-1 in batch shake flasks (A) Culture growth; (B) Viability.

FIG. 23 depicts the galactosylation profile of mAb #1 in CDM GIA-1 in batch shake flasks (A) NGA2F+NGA2F-GlcNac; (B) NA1F+NA2F.

FIG. 24 summarizes the effect of manganese and/or galactose addition to CDM GIA-1 on galactosylation of mAb #1 relative to control.

FIG. 25 depicts culture performance of CHO cell line producing mAb #2 in CDM GIA-1 in fed-batch 3L bioreactors (A) Culture growth; (B) Viability; (C) Normalized titer.

FIG. 26 depicts the glycosylation profile of mAb #2 in CDM GIA-1 in fed-batch 3L bioreactors (A) NGA2F+NGA2F-GlcNAc; (B) NA1F+NA2F.

FIG. 27 summarizes the effect of manganese and/or galactose addition to CDM GIA-1 on galactosylation of mAb #2 relative to control.

DETAILED DESCRIPTION

OF THE INVENTION

The present invention relates to methods modulating the glycosylation profile of recombinantly-expressed proteins. In particular, the present invention relates to methods of controlling (e.g., modulating) the galactosylation profile of recombinantly-expressed proteins by supplementing production medium, e.g., a hydrolysate-based or a CD medium, with manganese and/or galactose. For example, but not by way of limitation, the present invention demonstrates that supplementation of particular ranges of manganese and/or galactose concentrations to chemically defined media can be used to fine-tune the galactosylation profile of monoclonal antibodies produced in CHO and NSO cell lines. Similarly, supplementation of galactose alone to hydrolysate-based media is effective to modulate the galactosylation profile of the monoclonal antibody adalimumab produced in a CHO cell line in a concentration dependent manner. In view of such findings, the methods disclosed herein can be used to modulate the galactose content of recombinant proteins by controlling the amounts of manganese and/or galactose present in cell culture media. The studies described herein have also established that the changes in the galactosylation profiles obtained via implementation of the methods of the present invention are not only scale (1.5 L vs. 200 mL) and process independent (fed-batch in controlled bioreactor environment vs. batch in shake flasks), but also that no significant impact on culture growth and productivity is observed for most conditions studied.

A terminal galactose is added to NGA2F by β-galactosyltransferase enzyme in the presence of manganese chloride, to produce NA1F (in the case of an addition of a single terminal galactose) or NA2F (in the case of an addition of two terminal galactose molecules). This galactosyltransferase-mediated reaction employs UDP-galactose as the sugar substrate and Mn2+ as a cofactor for galactosyltransferase. Thus, without being bound by theory, it is believed that a change in protein homogeneity taking the form of an increase in the fraction of N-linked oligosaccharide NGA2F and a decrease in the fraction of NA1F+NA2F N-linked oligosaccharides could be caused by either an insufficient amount of the substrate (UDP-galactose), the cofactor for galactosyltransferase (Mn2+), or both.

In certain embodiments, the present invention is directed to methods of controlling the galactosylation profile of recombinantly-expressed proteins by supplementing a production medium, e.g., a hydrolysate-based or a CD medium, used in the production of recombinantly-expressed proteins with a sufficient amount of manganese and/or a manganese-containing supplement to achieve at least about the following manganese concentrations in the production media: at least about 0.1, at least about 0.2, at least about 0.5, at least about 1.0, at least about 10, at least about 20, at least about 25, at least about 40, at least about 50, at least about 60, at least about 75, at least about 80, or at least about 100 μM, wherein that production media is used to dilute a supplement-free cell culture growth media containing no supplement by a ratio of about 1:4 or about 1:5 (supplement-free growth media:supplemented production media). In certain embodiments, the present invention is directed to methods of controlling the galactosylation profile of recombinantly-expressed proteins by supplementing a production medium, e.g., a hydrolysate-based or a CD medium, used in the production of recombinantly-expressed proteins with sufficient galactose and/or galactose-containing supplement to achieve at least about the following galactose concentrations in the production media: at least about 1, at least about 4, at least about 5, at least about 10, at least about 15, at least about 20, at least about 30, at least about 40, at least about 60, or at least about 100 mM, wherein that production media is used to dilute a supplement-free cell culture growth media containing no supplement by a ratio of about 1:4 or about 1:5 (supplement-free growth media:supplemented production media).

In certain embodiments, the production medium, e.g., a hydrolysate-based or a CD medium, used in the production of a recombinantly-expressed protein is supplemented with manganese and not galactose. For the shake flasks studies in Example 1, but not by way of limitation, addition of manganese and not galactose to production IVGN CDM GIA-1 lowered the NGA2F+NGA2F-GlcNac sum by 6% to 9% and increased the NA1F+NA2F sum by 8% to 9% (FIGS. 3, 4, and 5). No further increase in manganese concentration was explored in the experimental design due to the growth inhibition observed at about 100 μM.

In certain embodiments, the production medium, e.g., a hydrolysate-based or a CD medium, used in the production of a recombinantly-expressed protein is supplemented with galactose and not manganese. For the shake flasks studies in Example 1, but not by way of limitation, addition of galactose only to production IVGN CDM GIA-1 lowered the NGA2F+NGA2F-GlcNac sum by 3% to 7% and increased NA1F+NA2F by 3% to 7% (FIGS. 3, 4, and 5). These findings indicate that a manganese concentration of about 100 μM and a galactose concentration of about 100 mM represent the maximum range of interest for this Example 1.

In certain embodiments, the production medium, e.g., a hydrolysate-based media or a CD media, used in the production of a recombinantly-expressed protein is supplemented with both manganese and galactose. For example, but not by way of limitation, the studies outlined in Example 1 indicate that the addition of combinations of manganese and galactose to production IVGN CDM GIA-1 resulted in a significant decrease in the NGA2F+NGA2F-GlcNac sum of 11% to 26% and a corresponding significant increase in the NA1F+NA2F sum of 13% to 23% as compared to the control condition where no manganese or galactose were added to the production media (FIGS. 3, 4, and 5). The effect on modulation of galactosylation of adalimumab in production IVGN CDM GIA-1 with the combined addition of manganese chloride and galactose was synergistic. In particular, the combined addition of manganese chloride and galactose decreased the NGA2F+NGA2F-GlcNac sum and increased the NA1F+NA2F sum by a larger percentage than by adding manganese or galactose alone and summing up their individual effects. For example, but not by way of limitation, addition of 40 μM manganese chloride alone reduced the NGA2F sum by 6%, and addition of 40 mM galactose alone decreased the NGA2F+NGA2F-GlcNac sum by 6%. However, the combined addition of manganese chloride and galactose at these same concentrations (i.e. 40 μM manganese+40 mM galactose) led to an 18% reduction in the NGA2F+NGA2F-GlcNac sum, 6% higher than their combined individual contributions to the reduction of the NGA2F+NGA2F-GlcNac sum. We define this effect as being synergistic and maintain this definition throughout the invention. The largest percent decrease in the NGA2F+NGA2F-GlcNac sum of approximately 26% was observed with the combined addition of 100 μM manganese chloride and 100 mM galactose. The largest percent increase in the NA1F+NA2F sum of approximately 23% was recorded with the combined addition of 60 μM manganese chloride and 100 mM galactose.

For the fed-batch bioreactor study described in Example 1, two manganese chloride and galactose combinations were studied and the results indicate that the decrease in the NGA2F+NGA2F-GlcNac sum and the corresponding increase in the NA1F+NA2F sum was scale (1.5 L vs. 200 mL) and process independent (fed-batch in controlled bioreactor environment vs. batch in shake flasks). For example, but not by way of limitation, the combined addition of 40 μM manganese chloride and 20 mM galactose to both production basal CDM GIA-1 and feed CDM JCL-5 decreased the NGA2F+NGA2F-GlcNac sum by 26% and increased the NA2F+NA2F sum by 27% compared to the control cultures (FIG. 6). A further increase in the galactose concentration to 40 mM in addition to manganese supplementation at 40 μM concentration resulted in an additional 3% decrease in the NGA2F+NGA2F-GlcNac sum, and a corresponding 3% increase in the NA1F+NA2F sum

In certain embodiments, the present invention is directed to the supplementation of CD media used in the production of a recombinantly-expressed protein with galactose and/or manganese. That such supplementation is effective across distinct CD media is evidenced by the results outlined in Example 2. Specifically, Example 2 results indicate that the addition of manganese chloride alone within the range of 0 to 40 μM to production CDM HyClone CDM4CHO decreased the NGA2F+NGA2F-GlcNac sum by a maximum of 5% in a concentration dependent manner (FIG. 8). A comparable maximum increase of 4% in the NA1F+NA2F sum was also achieved. Addition of galactose alone up to a maximum concentration of 40 mM yielded a 6% maximum decrease in the NGA2F+NGA2F-GlcNac sum and a corresponding 6% increase in the NA1F+NA2F sum. Modulation of galactosylation was also observed in production CDM HyClone CDM4CHO cultures supplemented with both manganese chloride and galactose. An additive effect was observed in cultures supplemented with both manganese chloride and galactose. The combined addition of manganese chloride and galactose decreased the NGA2F+NGA2F-GlcNac sum and increased the NA1F+NA2F sum by a comparable percentage as when manganese or galactose were added alone and their individual effects were summed up (FIG. 9). For example, but not by way of limitation, addition of 40 μM manganese chloride alone reduced the NGA2F+NGA2F-GlcNac sum by 5%, and addition of 40 mM galactose alone decreased the NGA2F sum by 6%. The combined addition of manganese chloride and galactose at these same concentrations (i.e. 40 μM manganese+40 mM galactose) led to a 12% reduction in the NGA2F+NGA2F-GlcNac sum. We define this effect as being additive and maintain this definition throughout the invention. The highest percentage decrease in the NGA2F sum of 12% and the corresponding 11% increase in the NA1F+NA2F sum was observed for the culture supplemented with 40 μM manganese chloride and 40 mM galactose.

In certain embodiments, the present invention is directed to the supplementation of a hydrolysate-based media used in the production of a recombinantly-expressed protein with galactose and/or manganese. For example, as outlined in Example 3, the addition of manganese chloride alone within the range of 0 to 40 μM to hydrolysate-based production media decreased the NGA2F+NGA2F-GlcNac sum by approximately 1%, although that change is within the oligosaccharide assay variability (FIG. 11). The addition of galactose alone up to a maximum concentration of 40 mM yielded a maximum decrease of 4% in the NGA2F+NGA2F-GlcNac sum and a corresponding 4% maximum increase in the NA1F+NA2F sum. Such oligosaccharide profile changes achieved with the addition of galactose alone are comparable to the changes recorded when combinations of galactose and manganese chloride were added to the hydrolysate-based media. For example, the combined addition of manganese chloride ranging from 0 to 40 μM and galactose ranging from 0 to 40 mM to hydrolysate-based media led to an approximate 5% maximum decrease in the NGA2F+NGA2F-GlcNac sum and a corresponding 3% increase in the NA1F+NA2F sum (FIG. 12). The highest percentage decrease of 5% in the NGA2F+NGA2F-GlcNac sum and the corresponding 4% increase in the NA1F+NA2F sum was observed for the culture supplemented with 40 mM galactose and either 20 μM or 40 μM manganese chloride.

The compositions and methods of the present invention also find use across distinct cell lines. For example, but not by way of limitation, the study described in Example 4 illustrates that the supplementation of a CD media, GIA-1, with galactose and/or manganese is effective to modulate galactosylation of adalimumab produced using a CHO cell line distinct from that employed in Examples 1-3. For example, but not by way of limitation, when using this alternative cell line, the addition of manganese chloride alone within the range of 0 to 20 μM to production CDM GIA-1 decreased the NGA2F+NGA2F-GlcNac sum in a concentration dependent manner and increased the NA1F+NA2F sum by approximately the same percentage. A maximum decrease of 22% in the NGA2F+NGA2F-GlcNac sum and a maximum corresponding increase of 23% in the NA1F+NA2F sum was observed with the addition of 20 μM manganese chloride (FIG. 14). Similarly, a concentration dependent decrease in the NGA2F+NGA2F-GlcNac sum and a corresponding increase in the NA1F+NA2F sum was observed with the addition of galactose alone in the range of 0 to 20 mM. A maximum decrease of 9% in the NGA2F+NGA2F-GlcNac sum and a corresponding maximum increase of 10% in the NA1F+NA2F sum was observed with the addition of 20 mM galactose. Similarly, an additive effect was observed for the oligosaccharide profiles of adalimumab produced in cultures supplemented with the combined addition of manganese chloride and galactose to GIA-1 media (FIG. 15). For example, but not by way of limitation, addition of 10 μM manganese chloride alone reduced the NGA2F+NGA2F-GlcNac sum by 18%, and addition of 10 mM galactose alone decreased the NGA2F+NGA2F-GlcNac sum by 6%. The combined addition of manganese chloride and galactose at these same concentrations led to a 24% reduction in the NGA2F+NGA2F-GlcNac sum. The highest percentage decrease of 35% in the NGA2F+NGA2F-GlcNac sum and the corresponding increase of 37% in the NA1F+NA2F sum were observed for the culture supplemented with 40 μM manganese chloride and 20 mM galactose.

That the compositions and methods of the present invention also find use across distinct cell lines is further reinforced by the results of Example 5, which employs a third adalimumab-producing cell line that is distinct from either of the adalimumab-producing cell lines of Examples 1-4. For example, but not by way of limitation, when using this third cell line, the addition of manganese chloride alone within the range of 0 to 1 μM to production CDM GIA-1 decreased the NGA2F+NGA2F-GlcNac sum in a concentration dependent manner and increased the NA1F+NA2F sum by approximately the same percentage. A maximum decrease of 26% in the NGA2F+NGA2F-GlcNac and a corresponding increase of 28% in the NA1F+NA2F oligosaccharides were observed with the addition of 1 μM manganese chloride (FIG. 17). The addition of galactose alone at 30 mM concentration to production CDM GIA-1 decreased the NGA2F+NGA2F-GlcNac sum by 4% and increased the NA1F+NA2F sum by 3%. Furthermore, when manganese chloride and galactose were supplemented together into the production basal and feed media, the results demonstrated a synergistic benefit towards the decrease in the NGA2F+NGA2F-GlcNAc and the increase in the NA1F+NA2F oligosaccharides which is consistent with the results demonstrated in Example 1 (FIG. 18). For example, but not by way of limitation, at 0.2 μM manganese chloride plus 30 mM galactose the observed 25% decrease in the NGA2F+NGA2F-GlcNAc sum was 6% more than the sum of the decrease observed with the addition of 0.2 μM manganese chloride alone (15%) and that of 30 mM galactose alone (4%). Similarly, the resulting 24% increase in the NA1F+NA2F sum was more than the sum of the increase observed with the addition of 0.2 μM manganese chloride alone (16%) and that of 30 mM galactose alone (3%). The combined supplementation of 0.5 μM manganese chloride+30 mM galactose also demonstrated a synergistic effect on the galactosylation profile of adalimumab produced in this third cell line. A maximum decrease compared to the control condition of 34% in the NGA2F+NGA2F-GlcNac and a corresponding 34% maximum increase in the NA1F+NA2F oligosaccharides was observed with the combined addition of 0.5 μM manganese chloride and 30 mM galactose to chemically defined GIA-1 media.

That the compositions and methods of the present invention also find use across distinct types of cell lines is further reinforced by the results of Example 6, which employs a fourth adalimumab-producing cell line that is distinct from the adalimumab-producing cell lines of Examples 1-5, in that it is an NSO cell line. For example, but not by way of limitation, when using this NSO cell line, the addition of manganese chloride alone within the range of 0 to 0.5 μM to production CDM PFBM-3/PFFM-4 decreased the NGA2F+NGA2F-GlcNac sum in a concentration dependent manner and increased the NA1F+NA2F sum by approximately the same percentage. A maximum decrease of 18% in the NGA2F+NGA2F-GlcNac sum and a corresponding increase of 20% in the NA1F+NA2F sum were observed with the addition of 0.5 μM manganese chloride (FIG. 20). However, manganese doses greater than 0.5 μM were not explored further due to cytotoxicity effects. Similarly, a concentration dependent decrease in the NGA2F+NGA2F-GlcNac sum and a corresponding increase in the NA1F+NA2F sum were observed with the addition of galactose alone in the range of 0 to 10 mM to production CDM PFBM-3/PFFM-4. A maximum decrease of 14% in the NGA2F+NGA2F-GlcNac sum and a corresponding increase of 15% in the NA1F+NA2F sum was observed with the addition of 10 mM galactose. In addition, the effect on modulation of galactosylation of adalimumab produced in a NSO cell line in production CDM PFBM-3/PFFM-4 supplemented with manganese chloride and galactose was synergistic (FIG. 21). For example, but not by way of limitation, addition of 0.2 μM manganese chloride alone reduced the NGA2F+NGA2F-GlcNac sum by 12%, and addition of 4 mM galactose alone decreased the NGA2F+NGA2F-GlcNac sum by 2%. However, the combined addition of manganese chloride and galactose at these same concentrations (i.e. 0.2 μM manganese+4 mM galactose) led to a 19% reduction in the NGA2F+NGA2F-GlcNac sum, 5% higher than their combined individual contributions. A maximum decrease of ˜26% in the NGA2F+NGA2F-GlcNac sum and a corresponding 28% increase in the NA1F+NA2F sum were observed with the combined addition of 0.5 μM manganese chloride and 4 mM galactose.

The compositions and methods of the present invention also find use in the production of diverse antibodies, as evidenced by the results of Example 7, which employs a CHO cell line that produced an antibody distinct from adalimumab. For example, but not by way of limitation, when producing this antibody distinct from adalimumab, the addition of manganese chloride alone within the range of 0 to 40 μM to production CDM GIA-1 decreased the NGA2F+NGA2F-GlcNac sum by a maximum of 26% (FIG. 23). A comparable maximum increase of 27% in the NA1F+NA2F sum was also achieved. Addition of galactose alone up to a maximum concentration of 40 mM yielded a maximum decrease of 12% in the NGA2F+NGA2F-GlcNac sum and a corresponding 13% maximum increase in the NA1F+NA2F sum in a concentration dependent manner. In addition, the combined addition of galactose and manganese chloride to production CDM GIA-1 resulted in a greater percent reduction in the NGA2F+NGA2F-GlcNac sum and, correspondingly, a greater percent increase in the NA1F+NA2F sum as compared to the addition of either component alone (FIG. 24). For example, but not by way of limitation, the addition of 40 μM manganese chloride alone reduced the NGA2F+NGA2F-GlcNac sum by 20%, and the addition of 40 mM galactose alone decreased the NGA2F+NGA2F-GlcNac sum by 12%. However, the combined addition of manganese chloride and galactose at these same concentrations (i.e. 40 μM manganese+40 mM galactose) led to a 27% decrease in the NGA2F+NGA2F-GlcNac sum. The highest percentage decrease of 32% in the NGA2F+NGA2F-GlcNac sum and the corresponding increase of 30% in the NA1F+NA2F sum were observed for the culture supplemented with 20 μM manganese chloride and 20 mM galactose.

That the compositions and methods of the present invention also find use when producing diverse antibodies is further reinforced by the results of Example 8, which employs a CHO cell line producing an antibody distinct from both adalimumab and the antibody of Example 7. For example, but not by way of limitation, when producing this third antibody, the addition of manganese chloride alone in the range of 0 to 75 μM to production CDM GIA-1 decreased the NGA2F+NGA2F-GlcNac sum by a maximum of 18% (FIG. 26). A comparable maximum increase of 16% in the NA1F+NA2F sum was also achieved. Addition of galactose alone up to a maximum concentration of 60 mM yielded a maximum decrease of 12% in the NGA2F+NGA2F-GlcNac sum and a corresponding 11% maximum increase in the NA1F+NA2F sum. In addition, when manganese chloride and galactose were supplemented together into the basal and feed media, the results demonstrated at least an additive effect and sometimes a synergistic effect towards the decrease in the NGA2F+NGA2F-GlcNAc sum and the increase in the NA1F+NA2F sum (FIG. 27). The synergistic effect was observed for the condition supplemented with 25 μM manganese chloride and 15 mM galactose. The observed 22% decrease in the NGA2F+NGA2F-GlcNAc sum was 5% more than the sum of the decrease observed with the addition of 25 μM manganese chloride alone (10%) and 15 mM galactose alone (7%). The additive effect was observed for the condition supplemented with 50 μM manganese chloride and 30 mM galactose. The observed 28% decrease in the NGA2F+NGA2F-GlcNAc sum was comparable to the sum of the decrease observed with the addition of 50 μM manganese chloride alone (18%) and 30 mM galactose alone (12%). A maximum decrease of 28% in the NGA2F+NGA2F-GlcNac and a corresponding 25% maximum increase in the NA1F+NA2F sum compared to the control condition was observed with the combined addition of 50 μM manganese chloride and 30 mM galactose to chemically defined GIA-1 media.

Although specifically directed to the production of antibodies, the following description outlines general techniques that can be adapted for the production of other recombinantly-expressed proteins. For example, to express a recombinant antibody, nucleic acids encoding partial or full-length light and heavy chains are inserted into one or more expression vector such that the genes are operatively linked to transcriptional and translational control sequences. (See, e.g., U.S. Pat. No. 6,914,128, the entire teaching of which is incorporated herein by reference.) In this context, the term “operatively linked” is intended to mean that an antibody gene is ligated into a vector such that transcriptional and translational control sequences within the vector serve their intended function of regulating the transcription and translation of the antibody gene. The expression vector and expression control sequences are chosen to be compatible with the expression host cell used. The antibody light chain gene and the antibody heavy chain gene can be inserted into a separate vector or, more typically, both genes are inserted into the same expression vector. The antibody genes are inserted into an expression vector by standard methods (e.g., ligation of complementary restriction sites on the antibody gene fragment and vector, or blunt end ligation if no restriction sites are present). Prior to insertion of the antibody or antibody-related light or heavy chain sequences, the expression vector may already carry antibody constant region sequences. For example, one approach to converting particular VH and VL sequences to full-length antibody genes is to insert them into expression vectors already encoding heavy chain constant and light chain constant regions, respectively, such that the VH segment is operatively linked to the CH segment(s) within the vector and the VL segment is operatively linked to the CL segment within the vector. Additionally or alternatively, the recombinant expression vector can encode a signal peptide that facilitates secretion of the antibody chain from a host cell. The antibody chain gene can be cloned into the vector such that the signal peptide is linked in-frame to the amino terminus of the antibody chain gene. The signal peptide can be an immunoglobulin signal peptide or a heterologous signal peptide (i.e., a signal peptide from a non-immunoglobulin protein).

In addition to the antibody chain genes, a recombinant expression vector of the invention can carry one or more regulatory sequence that controls the expression of the antibody chain genes in a host cell. The term “regulatory sequence” is intended to include promoters, enhancers and other expression control elements (e.g., polyadenylation signals) that control the transcription or translation of the antibody chain genes. Such regulatory sequences are described, e.g., in Goeddel; Gene Expression Technology: Methods in Enzymology 185, Academic Press, San Diego, Calif. (1990), the entire teaching of which is incorporated herein by reference. It will be appreciated by those skilled in the art that the design of the expression vector, including the selection of regulatory sequences may depend on such factors as the choice of the host cell to be transformed, the level of expression of protein desired, etc. Suitable regulatory sequences for mammalian host cell expression include viral elements that direct high levels of protein expression in mammalian cells, such as promoters and/or enhancers derived from cytomegalovirus (CMV) (such as the CMV promoter/enhancer), Simian Virus 40 (SV40) (such as the SV40 promoter/enhancer), adenovirus, (e.g., the adenovirus major late promoter (AdMLP)) and polyoma. For further description of viral regulatory elements, and sequences thereof, see, e.g., U.S. Pat. No. 5,168,062 by Stinski, U.S. Pat. No. 4,510,245 by Bell et al. and U.S. Pat. No. 4,968,615 by Schaffner et al., the entire teachings of which are incorporated herein by reference.

In addition to the antibody chain genes and regulatory sequences, a recombinant expression vector of the invention may carry one or more additional sequences, such as a sequence that regulates replication of the vector in host cells (e.g., origins of replication) and/or a selectable marker gene. The selectable marker gene facilitates selection of host cells into which the vector has been introduced (see e.g., U.S. Pat. Nos. 4,399,216, 4,634,665 and 5,179,017, all by Axel et al., the entire teachings of which are incorporated herein by reference). For example, typically the selectable marker gene confers resistance to drugs, such as G418, hygromycin or methotrexate, on a host cell into which the vector has been introduced. Suitable selectable marker genes include the dihydrofolate reductase (DHFR) gene (for use in dhfr-host cells with methotrexate selection/amplification) and the neo gene (for G418 selection).

An antibody, or antibody portion, of the invention can be prepared by recombinant expression of immunoglobulin light and heavy chain genes in a host cell. To express an antibody recombinantly, a host cell is transfected with one or more recombinant expression vectors carrying DNA fragments encoding the immunoglobulin light and heavy chains of the antibody such that the light and heavy chains are expressed in the host cell and secreted into the medium in which the host cells are cultured, from which medium the antibodies can be recovered. Standard recombinant DNA methodologies are used to obtain antibody heavy and light chain genes, incorporate these genes into recombinant expression vectors and introduce the vectors into host cells, such as those described in Sambrook, Fritsch and Maniatis (eds), Molecular Cloning; A Laboratory Manual, Second Edition, Cold Spring Harbor, N.Y., (1989), Ausubel et al. (eds.) Current Protocols in Molecular Biology, Greene Publishing Associates, (1989) and in U.S. Pat. Nos. 4,816,397 & 6,914,128, the entire teachings of which are incorporated herein.

For expression of the light and heavy chains, the expression vector(s) encoding the heavy and light chains is (are) transfected into a host cell by standard techniques. The various forms of the term “transfection” are intended to encompass a wide variety of techniques commonly used for the introduction of exogenous DNA into a prokaryotic or eukaryotic host cell, e.g., electroporation, calcium-phosphate precipitation, DEAE-dextran transfection and the like. Although it is theoretically possible to express the antibodies of the invention in either prokaryotic or eukaryotic host cells, expression of antibodies in eukaryotic cells, such as mammalian host cells, is suitable because such eukaryotic cells, and in particular mammalian cells, are more likely than prokaryotic cells to assemble and secrete a properly folded and immunologically active antibody. Prokaryotic expression of antibody genes has been reported to be ineffective for production of high yields of active antibody (Boss and Wood (1985) Immunology Today 6:12-13, the entire teaching of which is incorporated herein by reference).

Suitable host cells for cloning or expressing the DNA in the vectors herein are the prokaryote, yeast, or higher eukaryote cells described above. Suitable prokaryotes for this purpose include eubacteria, such as Gram-negative or Gram-positive organisms, e.g., Enterobacteriaceae such as Escherichia, e.g., E. coli, Enterobacter, Erwinia, Klebsiella, Proteus, Salmonella, e.g., Salmonella typhimurium, Serratia, e.g., Serratia marcescans, and Shigella, as well as Bacilli such as B. subtilis and B. licheniformis (e.g., B. licheniformis 41P disclosed in DD 266,710 published Apr. 12, 1989), Pseudomonas such as P. aeruginosa, and Streptomyces. One suitable E. coli cloning host is E. coli 294 (ATCC 31,446), although other strains such as E. coli B, E. coli X1776 (ATCC 31,537), and E. coli W3110 (ATCC 27,325) are suitable. These examples are illustrative rather than limiting.

In addition to prokaryotes, eukaryotic microbes such as filamentous fungi or yeast are suitable cloning or expression hosts for polypeptide encoding vectors. Saccharomyces cerevisiae, or common baker\'s yeast, is the most commonly used among lower eukaryotic host microorganisms. However, a number of other genera, species, and strains are commonly available and useful herein, such as Schizosaccharomyces pombe; Kluyveromyces hosts such as, e.g., K. lactis, K. fragilis (ATCC 12,424), K. bulgaricus (ATCC 16,045), K. wickeramii (ATCC 24,178), K. waltii (ATCC 56,500), K. drosophilarum (ATCC 36,906), K. thermotolerans, and K. marxianus; yarrowia (EP 402,226); Pichia pastoris (EP 183,070); Candida; Trichoderma reesia (EP 244,234); Neurospora crassa; Schwanniomyces such as Schwanniomyces occidentalis; and filamentous fungi such as, e.g., Neurospora, Penicillium, Tolypocladium, and Aspergillus hosts such as A. nidulans and A. niger.

Suitable host cells for the expression of glycosylated antibodies are derived from multicellular organisms. Examples of invertebrate cells include plant and insect cells. Numerous baculoviral strains and variants and corresponding permissive insect host cells from hosts such as Spodoptera frugiperda (caterpillar), Aedes aegypti (mosquito), Aedes albopictus (mosquito), Drosophila melanogaster (fruitfly), and Bombyx mori have been identified. A variety of viral strains for transfection are publicly available, e.g., the L-1 variant of Autographa californica NPV and the Bm-5 strain of Bombyx mori NPV, and such viruses may be used as the virus herein according to the present invention, particularly for transfection of Spodoptera frugiperda cells. Plant cell cultures of cotton, corn, potato, soybean, petunia, tomato, and tobacco can also be utilized as hosts.

Suitable mammalian host cells for expressing the recombinant antibodies of the invention include Chinese Hamster Ovary (CHO cells) (including dhfr-CHO cells, described in Urlaub and Chasin, (1980) PNAS USA 77:4216-4220, used with a DHFR selectable marker, e.g., as described in Kaufman and Sharp (1982) Mol. Biol. 159:601-621, the entire teachings of which are incorporated herein by reference), NS0 myeloma cells, COS cells and SP2 cells. When recombinant expression vectors encoding antibody genes are introduced into mammalian host cells, the antibodies are produced by culturing the host cells for a period of time sufficient to allow for expression of the antibody in the host cells or secretion of the antibody into the culture medium in which the host cells are grown. Other examples of useful mammalian host cell lines are monkey kidney CV1 line transformed by SV40 (COS-7, ATCC CRL 1651); human embryonic kidney line (293 or 293 cells subcloned for growth in suspension culture, Graham et al., J. Gen Virol. 36:59 (1977)); baby hamster kidney cells (BHK, ATCC CCL 10); Chinese hamster ovary cells/−DHFR (CHO, Urlaub et al., Proc. Natl. Acad. Sci. USA 77:4216 (1980)); mouse sertoli cells (TM4, Mather, Biol. Reprod. 23:243-251 (1980)); monkey kidney cells (CV1 ATCC CCL 70); African green monkey kidney cells (VERO-76, ATCC CRL-1587); human cervical carcinoma cells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34); buffalo rat liver cells (BRL 3A, ATCC CRL 1442); human lung cells (W138, ATCC CCL 75); human liver cells (Hep G2, HB 8065); mouse mammary tumor (MMT 060562, ATCC CCL51); TRI cells (Mather et al., Annals N.Y. Acad. Sci. 383:44-68 (1982)); MRC 5 cells; FS4 cells; and a human hepatoma line (Hep G2), the entire teachings of which are incorporated herein by reference.

Host cells are transformed with the above-described expression or cloning vectors for antibody production and cultured in conventional nutrient media modified as appropriate for inducing promoters, selecting transformants, or amplifying the genes encoding the desired sequences.

The host cells used to produce an antibody may be cultured in a variety of media. Commercially available media such as Ham\'s F10™ (Sigma), Minimal Essential Medium™ ((MEM), (Sigma), RPMI-1640 (Sigma), and Dulbecco\'s Modified Eagle\'s Medium™ ((DMEM), Sigma) are suitable for culturing the host cells. In addition, any of the media described in Ham et al., Meth. Enz. 58:44 (1979), Barnes et al., Anal. Biochem. 102:255 (1980), U.S. Pat. Nos. 4,767,704; 4,657,866; 4,927,762; 4,560,655; or 5,122,469; WO 90/03430; WO 87/00195; or U.S. Pat. No. Re. 30,985 may be used as culture media for the host cells, the entire teachings of which are incorporated herein by reference. The culture conditions, such as temperature, pH, and the like, are those previously used with the host cell selected for expression, and will be apparent to the ordinarily skilled artisan.

Host cells can also be used to produce portions of intact antibodies, such as Fab fragments or scFv molecules. It is understood that variations on the above procedure are within the scope of the present invention. For example, in certain embodiments it may be desirable to transfect a host cell with DNA encoding either the light chain or the heavy chain (but not both) of an antibody of this invention. Recombinant DNA technology may also be used to remove some or all of the DNA encoding either or both of the light and heavy chains that is not necessary for antigen binding. The molecules expressed from such truncated DNA molecules are also encompassed by the antibodies of the invention. In addition, bifunctional antibodies may be produced in which one heavy and one light chain are an antibody of the invention and the other heavy and light chain are specific for an antigen other than the original antigen by crosslinking an antibody of the invention to a second antibody by standard chemical crosslinking methods.

In a suitable system for recombinant expression of an antibody, or antigen-binding portion thereof, of the invention, a recombinant expression vector encoding both the antibody heavy chain and the antibody light chain is introduced into dhfr-CHO cells by calcium phosphate-mediated transfection. Within the recombinant expression vector, the antibody heavy and light chain genes are each operatively linked to CMV enhancer/AdMLP promoter regulatory elements to drive high levels of transcription of the genes. The recombinant expression vector also carries a DHFR gene, which allows for selection of CHO cells that have been transfected with the vector using methotrexate selection/amplification. The selected transformant host cells are cultured to allow for expression of the antibody heavy and light chains and intact antibody is recovered from the culture medium. Standard molecular biology techniques are used to prepare the recombinant expression vector, transfect the host cells, select for transformants, culture the host cells and recover the antibody from the culture medium.

When using recombinant techniques, the antibody can be produced intracellularly, in the periplasmic space, or directly secreted into the medium. In one aspect, if the antibody is produced intracellularly, as a first step, the particulate debris, either host cells or lysed cells (e.g., resulting from homogenization), can be removed, e.g., by centrifugation or ultrafiltration. Where the antibody is secreted into the medium, supernatants from such expression systems can be first concentrated using a commercially available protein concentration filter, e.g., an Amicon™ or Millipore Pellicon™ ultrafiltration unit.

Prior to the process of the invention, procedures for purification of antibodies from cell debris initially depend on the site of expression of the antibody. Some antibodies can be secreted directly from the cell into the surrounding growth media; others are made intracellularly. For the latter antibodies, the first step of a purification process typically involves: lysis of the cell, which can be done by a variety of methods, including mechanical shear, osmotic shock, or enzymatic treatments. Such disruption releases the entire contents of the cell into the homogenate, and in addition produces subcellular fragments that are difficult to remove due to their small size. These are generally removed by differential centrifugation or by filtration. Where the antibody is secreted, supernatants from such expression systems are generally first concentrated using a commercially available protein concentration filter, e.g., an Amicon™ or Millipore Pellicon™ ultrafiltration unit. Where the antibody is secreted into the medium, the recombinant host cells can also be separated from the cell culture medium, e.g., by tangential flow filtration. Antibodies can be further recovered from the culture medium using the antibody purification methods of the invention.

6. EXAMPLES 6.1. Example 1 6.1.1. Materials & Methods

In the studies summarized in this example, we investigated the effects on product quality attributes resulting from the addition of manganese chloride and/or galactose to chemically defined Life Technologies Gibco, GIA-1, media (proprietary formulation) in the adalimumab-producing CHO cell line utilized in Example 3, but adapted to GIA-1 media. The studies were performed in either a batch process in shake flasks or a fed-batch process in 3L bioreactors.

Growth and production media for the adalimumab-producing CHO cell line were prepared using a proprietary Life Technologies Gibco chemically defined media, GIA-1. Basal production and feed media were supplemented with Manganese (II) Chloride (Sigma M1787—100 mL; 1.0 M±0.1 M) and D(+)Galactose (Sigma G5388—1 kg) according to the experimental design described in Table 1. All media were filtered through Corning 0.5 L or 1 L filter systems 0.22 μm Poly(Ether Sulfone) (PES) and stored at 4° C. until use.

The cell line utilized for both studies was generated from the adalimumab-producing CHO cell utilized in Example 3 by adapting it to chemically defined GIA-1 media for 7 (2 to 3 day each) passages in a combination of 250 mL and 500 mL Corning vented non-baffled shake flasks before freezing.

Upon thaw, for the batch shake flask study, cells were expanded for 3 to 5 (2 to 3 day each) passages in a combination of 250 mL and 500 mL Corning vented non-baffled shake flasks. Production cultures were initiated in duplicate 500 mL Corning vented non-baffled shake flasks (200 mL working volume) at an initial viable cell density (VCD) of approximately 0.5×106 cells/mL. Cultures were maintained on orbital shakers at 110 revolutions per minute (RPM) in a dry incubator at 35° C. and 5% CO2. The shake flask study was run in an extended batch mode by feeding a glucose solution (1.25% (v/v) of 40% solution) when the media glucose concentration fell below 3 g/L.

For the fed-batch bioreactor study, cells were expanded for 8 (2 to 3 day each) passages in Corning vented non-baffled shake flasks maintained on orbital shakers at 110 RPM and in 20 L cell bags (3L to 10 L working volume) maintained at 20-25 RPM, 7.5° angle, and 0.25 SLPM airflow in a dry incubator at 35° C. and 5% CO2. Production cultures were initiated in duplicate 3L bioreactors (1.5 L working volume) at 35° C., 30% dissolved oxygen, 200 RPM, pH ramp from 7.1 to 6.9 over 3 days, and pH setpoint of 6.9 thereafter. A fixed split ratio of cells to media of 1:5 was utilized to initiate the production stage cultures. In the fed-batch mode, a chemically-defined feed from Life Technologies Gibco, JCL-5 (proprietary formulation), was added as follows: 3% (v/v)—day 3, 5%—day 4, 7%—day 5, 10%—day 6, and 10%—day 7. Additional glucose (1.25% (v/v) of 40% solution) was fed when the media glucose concentration fell below 3 g/L.

For all studies with CHO cell lines described throughout this invention, samples were collected daily and measured for cell density and viability using a Cedex cell counter. Retention samples for titer analysis via Poros A method were collected by centrifugation at 12,000 RPM for 5 min when the culture viability began declining. The cultures were harvested by collecting 125 mL aliquots and centrifuging at 3,000 RPM for 30 min when culture viability was near or below 50%. All supernatants were stored at −80° C. until analysis.

For all studies, the harvest samples were Protein A purified and prepared for the oligosaccharide assay using the following procedures. As a first step in the process of establishing the identity and quantifying the oligosaccharides, they are released from the protein by enzymatic digestion with N-glycanase. Once the glycans are released, the free reducing end of each glycan is labeled by reductive amination with a fluorescent tag, 2-aminobenzamide (2-AB). The resulting labeled glycans are separated by normal-phase HPLC (NP-HPLC) in acetonitrile: 50 mM ammonium formate, pH 4.4, and detected by a fluorescence detector. Quantitation is based on the relative area percent of detected sugars. Throughout this invention, the relative area percentages of the agalactosyl fucosylated biantennary oligosaccharides, denoted as NGA2F+NGA2F-GlcNAc sum, and the galactose-containing fucosylated biantennary oligosaccharides NA1F+NA2F sum are reported and discussed.

6.1.2. Experimental Design

As detailed in Table 1, for the batch shake flask study, manganese chloride was supplemented at the following concentrations in production media: 0, 40, 60, 80, and 100 μM. Galactose was supplemented at the following levels in production media: 0, 10, 20, 40, and 100 mM. Individual and combined additions of manganese chloride and galactose were studied using a comprehensive design divided into 3 sets of experiments. Each experiment had a control culture for direct comparison of culture growth, productivity, and product quality. Production media used for the control cultures was not supplemented with manganese chloride or galactose. Culture growth, productivity, and product quality data for control cultures is the average of the 3 experiments.

For the fed-batch bioreactor study, manganese chloride and galactose were supplemented to both production and feed media in the following combinations: 40 μM manganese chloride and 20 mM galactose; 40 μM manganese chloride and 40 mM galactose (Table 2). Basal and feed media for the control cultures were not supplemented with manganese chloride or galactose.

TABLE 1 Experimental design for the batch shake flasks study (Example 1) Manganese Galactose (μM) (mM) ID 0 0 Mn(0) Gal(0) 0 10 Mn(0) Gal(10) 0 20 Mn(0) Gal(20) 0 40 Mn(0) Gal(40) 0 100 Mn(0) Gal(100) 40 0 Mn(40) Gal (0) 80 0 Mn(80) Gal(0) 100 0 Mn(100) Gal(0) 40 10 Mn(40) Gal(10) 40 20 Mn(40) Gal(20) 40 40 Mn(40) Gal(40) 40 100 Mn(40) Gal(100) 60 20 Mn(60) Gal(20) 60 40 Mn(60) Gal(40) 60 100 Mn(60) Gal(100) 80 20 Mn(80) Gal(20) 80 40 Mn(80) Gal(40)

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